HMRC said its "vision" is to provide online, "real-time services accessible from any device, any time, via the latest cloud technology".

The advert said it currently has a hugely complex IT estate, ranging from "state of the art" data analytics platforms to 40-year old systems. "The breadth, variety and complexity of these systems and the business processes they support are on a scale rarely seen in other global organisations," it said.

"The successful person will define and lead the implementation of a cloud-based strategy to deliver significant cost reduction and service performance improvement, alongside maintaining operational service and delivery of new projects," it said.

The job description described it as a "truly a unique opportunity". It said the candidate should be a "politically astute leader, with experience of delivering large (£50million+) infrastructure transformation projects, across complex IT systems". ®